With spread of an optical fiber communication system, an amount of information transmitted has dramatically increased. With the increase in the amount of information transmitted, high-capacity-long-distance optical communication is carried out using a large number of optical fibers such as a dozen or a hundred of optical fibers in the optical fiber communication system.
In order to increase transmission capacity per optical fiber in such an optical fiber communication system, it is known that plural signals are transmitted by light propagating through plural cores using a multicore fiber in which outer peripheries of the cores are surrounded with a single clad. In the optical fiber communication system, plural optical fibers may be connected for use to carry out long-distance optical communication. In addition, plural multicore fibers may be connected for use in the optical fiber communication system using a multicore fiber.
Patent Literature 1 describes a multicore fiber connection method. In the connection method described in the literature, connected portions at which end surfaces of multicore fibers to be connected butt each other are disposed between a pair of electrodes and the end surfaces of the optical fibers are fused to each other by causing the pair of electrodes to electrically discharge.
[Patent Literature 1] JP-A-203-210602